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Google Maps: USA Hot Springs

October 14, 2005 By Leave a Comment

A new Google Maps "mashup" is out, this one focusing on USA Hot Springs. I don’t usually post Google Maps mashups; so many other blogs cover the subject quite well. But much of my focus is on maps and the great outdoors, so I just couldn’t resist this one. I’m not a hot spings nut, but I have enjoyed a few, and they bring back fond memories. Except the one in Big Bend National Park where the NPS ranger threatened to bust everyone and got his jollies by shining his flashlight on the ladies!

Via Google Maps Mania.


Filed Under: Internet applications

Rechargeable batteries for your GPS

October 12, 2005 By Leave a Comment

For some time now, I’ve been wanting to research and blog about choosing recharegable batteries for your GPS receiver. This is one of the few topics I regret not covering in my book, GPS Mapping: Make Your Own Maps. I didn’t have to look far to research the subject. I turned to one of my favorite GPS/mapping software discussion boards and found this thread. The idea of being able to recharge batteries in only 15 minutes was quite enticing, so I went out and bought the suggested unit, a 15-minute charger from Energizer (Amazon link), which comes with 4 AA batteries. I got mine at Target, but as you can see from the link, Target is also selling them through Amazon.

I did a quick test with my GPS, a Garmin GPSMap 60CS (Amazon). Granted, it wasn’t the most scientific test, but I was pleased to get 20 hours out of two batteries, which is exactly what the unit is rated. I’m quite excited, since all four of my GPS receivers use AA batteries, as does my digital camera.


Filed Under: Accessories, Best of the boards, Hardware

Serial to USB converters and GPS receivers

October 9, 2005 By Leave a Comment

So you got a new laptop, which has no serial port, but your GPS came with a serial cable. What do you do? The answer lies in a serial to USB converter, but sometimes they don’t work at first. I’ve heard people say that some cheap models are problematic, and that you should buy a name brand. Generally speaking, I think this is good advice. But I’ve also heard of cheap brands working and name brands failing to. What is going on here? A thread on the Yahoo OziExplorer discussion board delved into the topic this past week. Here are a few key snippets from the discussion…

read more

Filed Under: Best of the boards, Hardware

Converting Google Maps searches to GPS waypoints in Internet Explorer

October 3, 2005 By Leave a Comment

Yesterday I posted about how to convert Google Maps search results to GPS waypoints. I said then that "I couldn’t get it working in IE." The author sent me a note on how to do it, and this is such a cool tool that I decided to put it in a new post. Just right-click on the GMapToGPX button on his site and select "Add to Favorites." Then do your search at local.google.com and then click your GMapToGPX favorite.  The rest of the instructions should work fine.

UPDATE from Josh:

I’ve updated the bookmarklet code to handle searches on maps.google.com, too. I haven’t tested it in IE, but I know it works in Firefox. You shouldn’t need to do anything to get the new code; it should automatically use the latest version. I had to clear my browser cache to get the new version, though, so if you still can’t get a GPX file for maps.google.com search results, try that.


Filed Under: Internet applications

Garmin acquires MotionBased.com

October 3, 2005 By Leave a Comment

Garmin announced this morning that it is acquiring MotionBased Technologies. MotionBased is an online GPS mapping service that offers a number of unique features. I’ve actually been using MotionBased for awhile now and plan to post a review in the near future.

I suppose this move should come as no surprise following this story last week. It appears that Garmin and MotionBased have had a cozy relationship for some time now, even sharing a booth at Outdoor Retailer this year.

UPDATE: Here is the MotionBased take on it, courtesy of their weblog, MBlog.

Filed Under: Garmin, Internet applications

Converting Google Maps search results to GPS waypoints

October 2, 2005 By 12 Comments

A while back I was travelling quite a bit, and I wanted to figure out where I could find free wifi while on the road. So I went to Google Maps and clicked "Local Search." I entered wifi in the "what" field and a city name in the "where" field and, like magic, I had a map with lots of wifi hot spots. But now what? I had a GPS. There had to be a way to convert these search results to waypoints so my GPS could guide me there. I searched for a converter, and though I found a couple, I couldn’t get them to work. After a little sleuthing, I’ve discovered one that works, and the trick to get it to do so. Thanks to Josh of Communications From Elsewhere for this great tool.  Here are step-by-step instructions for you…

  1. Get the GMapToGPX converter and drag it to your browser’s bookmark toolbar. Now Josh says it works in Firefox and Internet Explorer (IE). There’s a bookmark toolbar in the Firefox, and it works fine there. I couldn’t get it working in IE though. UPDATE: In IE, just right-click on the GMapToGPX button on his site and select "Add to Favorites."
  2. Go to local.google.com and enter a query. This is where I had problems. It works with local.google.com but not with maps.google.com. I have no idea why. Maybe a more tech-savvy reader can enlighten us. Regardless, you end up in Google Maps.
  3. Once the local search loads, click the GMapToGPX button on your toolbar. Or if you’re using IE, click the GMapToGPX Favorite. This opens an xml/gpx file.
  4. Copy this file to a text editor and save it with a .gpx extension (e.g., Saratoga wifi.gpx)
  5. Open this in your favorite GPX compatible mapping software and send it to your GPS. One caveat here. I could not open this in MapSource. I was successful in transferring it to TopoFusion, ExpertGPS and USAPhotoMaps. I was also able to transfer from those, into my GPS, and then into MapSource.
  6. Now, hit the road!

Hmm, I’ll be on the road again next weekend, so what do I want to do? Here’s an idea. Just imagine the possibilities…


Filed Under: Internet applications

Making custom (not counterfeit) maps for your GPS

September 27, 2005 By 44 Comments

There was a story last week about counterfeit GPS maps causing drivers to get lost in Shanghai, which was widely reported in mapping blogs (like GeoCarta and The Map Room) and discussion groups.  But what do they mean by counterfeit maps? Jesse at Very Spatial started to address this, saying "I disagree with their use of the word ‘fake’, inaccurate is more realistic."  You can make custom maps for your GPS that may be sloppy or deceptive, or they may be more accurate than what you can buy commercially.

Let’s take a look at how this is done. What follows is a brief overview of a subject covered in great detail in my book, GPS Mapping – Make Your Own Maps, which includes step-by-step instructions.

Why would you want to do this? Well, you might be traveling to a foreign country for which there are no good GPS maps. Or you might just want better topo maps than what is available commercially. This is a common problem for outdoor recreation enthusiasts, as almost all GPS maps are based on 1:100K scale data, the one exception being Garmin’s US Topo 24K series (Amazon), which only covers national parks. Garmin’s US wide product (Amazon) shows contour lines 130 feet apart. I don’t know about you, but I like to know if I’m about to ride my mountain bike off a 100′ cliff! And while the Magellan (Amazon) and Lowrance products show contour lines much closer together, they actually interpolate the 1:100K data to do so, which is misleading to say the least.

On to how to make custom GPS maps…

read more

Filed Under: Garmin, Lowrance, Magellan, Software

GPS reception indoors

September 19, 2005 By Leave a Comment

In our second "best of the boards" post, we examine why you might be able to receive GPS signals indoors. Last time, we learned how water impacts reception, but what about the roof over your head? This question was posted on Geocaching.com’s foums, aka Groundspeak. Their GPS Units and Software forum   is an excellent resource for anyone interested in GPS and mapping software. Peter, a geocacher, provided the best answer…

They come through my roof (plywood and spanish tiles on top) just fine too, and they also make it through typical fiberglass boat construction. Most materials are not good absorbers of microwaves, but anything with a high water content (incl. people) or metal will block the signals.

As a general rule, anything that will heat up readily in a microwave oven will also absorb the GPS signals although the frequencies are a little different (1.5 GHz for GPS and a little over 2 GHz for ovens).

So as long as the wood and shingles on your roof are dry they’ll pass the signals ok, but of course insulation with a metal foil layer would block them.

The physical reason why things with water absorb the signals is that water molecules are highly polarized with the oxygen end having a negative charge and the end with the two hydrogens having a positive charge. When the GPS signals go through water the oscillating electrical field of the microwaves cause the water molecules to rotate back and forth and this absorbs energy from the signals.

Here is the full thread.


Filed Under: Best of the boards, Hardware

Trip Report: Using GPS biking Mt. Diablo

September 17, 2005 By 2 Comments

This post launches a new category at GPS Tracklog — Trip Reports. The point isn’t to provide a trail guide, but rather to exhibit some of the ways to utilize your GPS. This report focuses on a circumnavigation of Mt. Diablo, a 3849′ peak that dominates the eastern side of the San Francisco Bay region.

My wife and I were in the area this past week doing GPS mapping demos, promoting my book, GPS Mapping – Make Your Own Maps. Since our days were open, we decided to get in a mid-week bike ride.  Living on California’s heat-deprived North Coast, we opted for a ride slightly inland. Mt. Diablo was our target, and since I didn’t know the area very well, I turned to a message board on mtbr.com for help. I wasn’t disappointed. Several people, especially EBrider helped out, designing an awesome loop that incorporated technical single track, loose and steep fire roads, and nearly 2,000′ of elevation gain.

EB sent me a track in the form of a .tpo file, which is a National Geographic TOPO! (Amazon link) file format. This, combined with the trail descriptions provided by EB and others at mtbr.com, gave me almost enough info to plan the trip, though I will admit to picking up a hard copy of a trail map so that I had good access to trail names and other features. Too bad the Mount Diablo Interpretive Association doesn’t have this map posted online. Online trail maps (often PDFs), combined with mapping software and aerial photos, are typically adequate for my purposes.

I took the track that EB sent and exported it from TOPO via my GPS (a real pain since TOPO makes you convert tracks to routes in order to export them). I then imported it into TopoFusion, which allowed me to see the track on a color aerial photo. USGS posts color urban aerial imagery for major US metropolitan regions online at TerraServer, with more locations being added on a frequent basis. These images are readily available in programs like TopoFusion and USAPhotoMaps, which add a better user interface and allow you to transfer data to and from your GPS. The color imagery extends into natural areas in many cases, and the detail is amazing, going down to 0.25 meters per pixel. Notice the waypoint (MDNPEAKTR) in the image at the right. Mt_diablo_2 You can see a fire road going off to the north from the waypoint and, while the online image isn’t as sharp as the original, you can actually make out single-track going off to the northeast!  The single-track leaves the image near the top of the right-side.

With TopoFusion, I traced the single-track as accurately as possible, and created waypoints for major trail junctions. I then loaded the waypoints and redrawn track to my GPS, making the track blue so that I could clearly distinguish it from the tracklog being created as I rode.
The only things left were to create a route to guide me from waypoint to waypoint, and generate a printed map. I’ve posted the ride at 4 meters per pixel (black & white) using TopoFusion’s PhotoFusion feature, which apparently doesn’t yet allow access to the color aerial imagery when using their HTML Image Map feature.

EDIT: I asked at the TopoFusion message board and found out that you can capture a color aerial .jpg and replace the one generated by TopoFusion. My Mt. Diablo PhotoFusion page now shows the color aerial at 4 meters/pixel..

If you want to to learn more about how to use GPS and mapping software, check out my book. It has chapters on National Geographic TOPO!, USA PhotoMaps and TopoFusion. And for those of you who want to know more about the ride itself, read on…

read more

Filed Under: Software, Trip report (TR)

Does heavy cloud cover affect GPS reception?

September 10, 2005 By 15 Comments

Here, in our first best of the boards post, I’m quoting from alt.satellite.gps. The question that was asked  was, does heavy cloud cover affect GPS reception?

Dave Patton, Canadian Coordinator of the Degree Confluence Project had posted the best answer as of this morning…

The GPS signals will not be affected by clouds, rain, fog,
snow, etc., because of the combination of their passing
through water vapour, and the signal wavelength meaning
they "pass through" rain etc.

On the other hand, water will block/attenuate GPS signals.
For example, you can’t receive GPS signals underwater, although
having a GPS receiver antenna very close to the water surface
may allow some reception.

Most cloth that would be covering a GPS receiver’s antenna
will pass GPS signals(e.g. backpack, jacket, etc.), but cloth
with a metallic component will block/attenuate the signals.

Cloth that covers a GPS receiver’s antenna and gets wet
(e.g. from rain) can also block/attenuate the GPS signals.
In fact, you don’t even need the cloth – water on the case
that covers the GPS receiver antenna can block/attenuate
the GPS signals. That water could be drops, and/or a film
of water. I’ve seen that happen myself, when using my etrex
Venture in the rain – the signals were weak/blocked, but
a quick drying-off of the GPS case over the antenna brought
the reception back, which then degraded again as water
accumulated on the case. Similarly, GPS signal reception
is degraded in wet forest canopy conditions compared to
when the forest canopy is dry.


Filed Under: Best of the boards, FAQs, Hardware
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